Experimental silicosis and silicotuberculosis induced by intravenous injection of silicon dioxide particles are characterized by extensive degenerative and necrotic processes in the liver parenchyma. After 6 months, fibrosis of portal tracts in silicotuberculosis and silicosis was 2.8- and 1.4-fold more pronounced that in BCG granulomatosis and silicosis, respectively. Depression of cellular and intracellular regeneration processes in the liver parenchyma was also observed.